By way of example, the expansion of the cellular coverage in emerging markets requires phone designs that are very low cost in both material and conversion cost. Furthermore, success in these markets will require phone designs that are compelling and competitive in terms of design, proportions and appearance. Existing low cost phone designs typically use design approaches that have additional major housing components and internal component stacking that result in increased thickness.
Common methods of phone construction typically incorporate separate display module assemblies and printed circuit board assemblies, loaded into a housing assembly that includes a back cover and a front cover typically secured with screws, snap fit parts, or similar interlocking means. Using multiple separate sub-module assemblies and housing structures can be expensive compared with low cost product demands of consumers.
Also, the telephone microphone audio port and the front and rear speaker ports must be well sealed. If the seals are broken there might be an unwanted path from speaker to microphone which causes unwanted echo sounds, or the loudness and frequency response could be affected. In conventional phones the front housing is used to seal the phone, but this approach adds cost and size to the phone.
Keypads are known to be used in many types of devices, including but not limited to, handheld devices such as cell phones, non-handheld devices such as desktop phones, and any other device that employs keys as part of a user interface. Problems can arise with keypad usability in mobile devices and other devices where, for example, a user is not looking at the keypad. Some handset devices are known that include bell keypad layouts that include the numbers 0-9 in addition to other function keys such as “send” keys and other function keys and include tactile key dividers. One example may be found on the PEBL™ flip phone sold by Motorola, Inc. Such phones may include raised silicone portions that are in s-curve shapes and corresponding mirrored s-curve shapes. The two shapes are separated down the center of the keypad such that non-horizontal numbers 1, 5 and 3 are surrounded by a plurality of the s-curve and mirrored s-curve raised silicone protrusions. As such, the raised protrusions may be in a parallel orientation above and below non-horizontal keypad numbers 1, 5 and 3 with a space between the s-portion and mirrored s-portion centered below center number of the phone such as numbers 2, 5, 8 and 0. This configuration can assist a user when they are not looking at the phone to provide suitable vertical tactile separation between numbers in a vertical direction. In a horizontal direction however since the raised silicone portion is curved a user may inadvertently slip down to a next row of numbers instead of selecting the number in the horizontal row. For example, numbers in the horizontal row 1, 2 and 3 versus numbers in the second horizontal row 4, 5 and 6 can potentially be inadvertently selected since the raised tactile separations curve down and between horizontal rows.
Other keypad designs are known which use, for example, the keys themselves such as raised thin buttons that extend in a straight line horizontally. However, since the raised portion serves as the key and since the raised portions are horizontally straight across, it can be difficult to distinguish horizontally which number is being selected without looking at the phone. Other designs are also known which employ raised depressible button that are configured in a “v” shape in a horizontal line configuration. However, as with the type above, these raised sections are the keys themselves and can require separate components for each of the keys resulting in separate pieces potentially increasing the cost of the device, increasing the manufacturing complexity of the device and decreasing the reliability of the device.
Accordingly, a need exists for an improved keypad.